Looks like a really nice car, interior looks super tidy from the pics, shame about the later s3 bumpers been fitted, but easily changed, not sure what is going on with the waistband trim though is it colour coded or has it been deleted ? hard to tell from the pics sadly

The body seam has been ground down. I don’t know, but I would think this would compromise the bond between the two body halves. I recall reading that the Stevens body eliminated the seam line by the upper body half overlapping the lower.

Yes sadly it does compromise the seam sadly ! Such a shame as i think the waistband trim makes the G cars look so iconic ! If it was done properly it would of been glassed from behind the panel to add strength, but not many cars had that done when owners decided to delete the seam, they just grind them off sadly

You can repair it by screwing or glueing flexible plastic strip along the seam, to which you just then cover with the black lotus trim, however as you say the risk of panel slpit/crack between upper and lower sections is still there sadly.